Method and imaging system for imaging the spatial distribution of an x-ray fluorescence marker

The invention describes a method of generating metabolic images of an investigation region (3) of a body (1) by irradiating an X-ray fluorescence marker in that region and detecting the resulting X-ray fluorescence with a fluorescence detector (30). A fan beam (12) is used as a source of primary X-radiation, thus allowing the scanning of a whole body slice (3) in one step. The fluorescence image may be directly measured, e.g. by mapping voxels (104) of the investigation region onto pixels (134) of the detector (130) with the help of a pinhole collimator (132), or it may be reconstructed by procedures of computed tomography. Moreover, a morphological image may be generated by simultaneously recording X-ray transmission through the body (1).